Dear virtual community,
This may be a really stupid question, but I am obsessed. Couple of weeks ago a lecturer asked me in a lecture: ”A-M, do cognitive (neuro)scientists really think that the female and male brains are different?” I said: “Yes, pretty much so. The empirical – for example anatomical – evidence seems to support that conception. There are also theories about the prenatal, perinatal and other mechanisms of sexual differentation in the brains”. (See for example the bible – i.e. Kandel and Schwartz.)
He seemed unhappy, since he (of course) wanted to know, whether cognitive neuroscientists really think that female and male _cognitions_ are different.
Well, I do not even know, how the question should be understood in the context of “hard core cognitive neurosciences”. Is it, for example, meaningful to ask “Are there any differences in female and male cognitions from the perspective of neurocomputational architecture?” (This morning I was pretty convinced that there are… Greetings from virtual reality to home!)
Of course, Simon Baron-Cohen (and Panksepp?) have been arguing for the suggestion that there are at least some differences (the hemisphere specialization and the systemic brain- hypothesis), but… I really do not know, what is going on in the current literature.
So, what do you think? Are the cognitions different? At what level are they different, if they are? And why? If not, why not?
Have fun,
Anna-Mari
what about Doreen Kimura’s book? (not the very latest research, but a place to start)Published by MIT press. She also has some papers available at her homepage. I think the book title is “Sex and Cognition”, but I”m not sure and haven’t got time to check now.
Sure, they’re different. A simple “yes” is good enough for anyone educated enough on the matter to be reading this blog. But for the layperson, who is probably interested for some antecdoctal reason, e.g., asking because he wants to know if his wife thinks differently from him, maybe it’s worth mentioning that there are deviations from these rules.
Most every difference (if not all of them) between men and women come from three surges of testosterone throughout the system. Women don’t get the surges. And men get them to different degrees, depending on variables like amount of testosterone receptors in their bodies. There are even men who lack these receptors so turn out to be volumptuous, yet infertile women.
Of course there are also the sociological stimuli that go into making us who and how we are, so there’s another brain-altering factor that would make men and women different neuroanatomically.
But, as I said above, I think it would be important to mention that if you had a “typical” male brain poster-child and the same for a female brain, and you compared their brain images with some random woman’s brain images, she might be atypical. You might not be able to tell if she was a man or woman just by comparing her images to those of “the” man and “the” woman brain images.
There is pretty overwhelming evidence that in some spatial cognition tasks (specifically, mental rotation), and in visuospatial memory tasks, men do better than women on average, and in some verbal memory tasks, women tend to do better than men. Those findings are so robust that I think they provide pretty good evidence of differences in cognition between the sexes, across the population. I don’t think it’s clear at all why these differences exist, though imaging studies have found right-left hemisphere processing differences between the sexes that might have something to do with it.
I think that men and women are not only dimorphic in visible phenotypic traits (average height, average weight…)in endophenotypes as well.
This lead to dimorphic expression in disease.
Women are more suceptible to suffer for breast cancer and men from cardiovascular disease. The role play by several hormones is also relevant in configuiring the neural harware (e.g. Simon Baron-Cohen and team studies on prenatal testosterone)and thereby in cognition. Men surpass women in spatio-visual abillites and in contrast women surpass men in memory location of objects and language development. And this is reflected in the neuroanatomical layout with sometimes gross divergences not only in brain activations as assesed by neuroimaging techniques but by cithoarquitecthonic studies too.
Evolutionary studies also point to the direction of specific context of adaptations for both sexes evolving sex-specific ways to cope with the socio-ecological niche.
But the real question is: wether evolution is halt or is persistenly exerting selective pressures on men and women via education, enviroment…
If it is the latter perhaps within generations those alledge differences dissapear definitely. (Though, we have not to see differences under the umbrella of “the battle of the sexes” jus only distinct solutions of mother nature to the same problem of survivility wich makes neither men or women superior to the other.)
Meanwhile, this is a controversial issue with political, sociological and ideological connotations(Lawrence H. Summers knows it very well).
A good scientific reference trying to disntangle this is Simon Levay.
Hi,
I think that if neuroscientists have empirical proofs to say that the female and male brains are different, they must believe it too. They have to work seriously, right?
(check my blog!)
Anibal and Chris,
Thanks for your insightful comments. However, one question: Anibal mentioned Baron-Cohen and his team-studies. If I remember correctly, B-C thinks that the cognitive architecture must be modular. (The story goes something like this: If female and male cognitions/brains are different, this requires modularity and so on…)
I am not sure, whether he means the “neural” or “cognitive” modularity, but anyway… So, what do you think – does the difference-talk make sense only in a context of modular cognitive architecture?
And then… this is just a general point, and it is not intended to be critize your comments.
The issue of evolutionary explations. Of course our brains are result of natural selection, but I still think these questions are complex enough without the speculations about the possible selection pressures 100000 years or 1000000 years ago. Needless to say, this methodological point is made by Chomsky, Hauser and Fitch. I know many people hate their papers, but I still think that Maestro got that one right…
There are many, many, many other problems in the context of evolutionary psychology. For example, the standard darwinistic argument requires the complexity- premise, for example that the common ancestor of humans and chimpanzees must be less complex than humans and chimpanzees. This is a methodological problem; how could we compare the degree of complexity (of brains or cognitions) between us and our common ancestors in an empirically plausible way… ( This idea is from a paper I have written together with Otto Lappi).
And of course – especially in this context – the issue of massive modularity. Does the evolutionary approach of female/male differences require the hypothesis of massively modular minds and so on…
I don´t know, it is such a mess. In Finnish we have this very nice expression “Ei mennä nyt siihen”, and it means basicly that perhaps this issue (=the evolutionary story about female and male differentiation) should not be discussed here… So, “Ei mennä nyt siihen”:).
In a rush,
a
Thanks, a very good tip. I´ll try to find it.
A
Hi Anna,
the modularity debate is controversial since the definiton provided by Fodor(1983)was too rigid and inflexible but neverthless still continue to be alive because neuroimaging evidence suggest brain specific activitations in response to specific stimuli (Kanwisher). My humble view is that the brain is a brilliant plastic and distributed machine using one single module to more than one cognitive function and viceversa.
But even if we reject using modular arguments the differentiated hormonal and neurohormonal release patterns in men and women could make sense to talk about differences in brain tissue responsible for different behaviours in men and women(e.g. oxitocyn in maternal behaviour to care the offspring)
I think Baron-Cohen refers to cognitive modularity but because cognition never ocurrs “in vacuo” some neural modularity is imply.
Human evolutionary studies are underway and multiple converging evidence is recovering human past reliable and objectivily. But if Chomsky, Hauser and Fitch have being said to be cautious on that, i´ll be cautious.
The methodlogical problem arised from the complexity argument could be circunvented by computational simulations in neural networks using genetic algorithms always constrained by data derived from comparative neuroanatomy, molecular clocks studies (studies on molecular evolution)describing those functional aminoacids that change slowly in producing proteins that in turn produce phenotype; in reference to those previously possed by ancestors which give us a comparative picture. Just we have to save the distance from molecules to cognition (¿unbridgeable? i don´t think so)
Quoting T. Dobzhabsky: “In biology nothing makes sense except in the light of evolution” So it is a must for us try to explain what ocurred 100000 years ago. The nobel prize in physics was awarded to scientists that studied the “big bang” aprx 13 billions years ago.
Greetings.
Moi,
There are so many things in your reply…
I´ll start with some conceptual issues. Perhaps we should separate the notions of _cognitive modularization_ and _neural localization_. It is one thing to ask, whether something is a cognitive module. It is another thing to ask, whether it can be functionally or anatomically localized into brains. ( By the way, four or five years ago, when Uttal published his book “ A New Phrenology” (or something like it?) there was this debate in Brain and Mind about these questions. )
And yes, it is true that the original notion of module in sense of Fodor 1983 was too “rigid” and so on. (I am not sure, whether Fodor actually meant that the list of 9 features was the list of sufficient and necessary conditions for modularity in the first place.) Anyway, in the current literature many authors seem to be accepting that (i)the domain specificity and (ii) informational encapsulation are the most important ones. (It must be understood that in the context of cognitive sciences the notion of modularity is important, because there is the discussion of the limits of computational modeling of cognitive processes (the frame problem- debate and so on).)
So, my original question about the sexual differences was actually about this. What do the authors say? There are differences at the brains, fine. And there are psychological theories about the differences at the level of cognitive psychology. Very good.
But – are there such theories of cognitive modules or central processes (if there are such processes in the first place) that can describe sexual differences at the level of cognitive processes understood as computational ones? I am neither interested in cognitive psychology nor folk psychology here… If we tried to capture the relevant features of this question, we may have to start by analyzing what are the relevant computational mechanisms in respect of certain cognitive tasks like spatial cognitive tasks or visual memory tasks mentioned by Chris. But how could we do that? Any suggestions:)?
And finally, the complexity argument. I am not sure, whether I understand your reply… What does the “could be circunvented” mean?
The problem is that there is no data available about the degree of complexity in our common ancestor`s cognition and probably no data about his brains either. And the comparative study cannot be done, because there is nothing where to start. The reverse engineering methodology is fragile here, right? And let me emphasize; this is a methodological problem mainly for _psychological_ theories, not to biological ones…
Anna-Mari
Your question is important -whether the alledged sexual differences are also extensible to computational strategies-
With respect to the complexity problem i have hope to persuade you (though we share many commonalities!) of the possibily of circunvent the complexity problem or plausible ways to dissolve it.I can say in my favor that we have many places to start.
First of all, i would like to remind for the sake of the main backdrop thesis upon wich we discuss that even feminist theorists concede some differences in what can be seen as operationalitions or measures of computational mechanisms, say, behaviours in response to information whatever they are.
For example, C. Gilligan found empirical differences in the way females approach ethical thinking when confronted with ethical cases or scenarios in contrast to males (1982)
For her, females always solve ethical problems by consensus in a talkative spirit with main actors. On the other hand, males always solve ethical problems using rules and principles.
I know that Guilligan is not a cognitive neuroscientist but his work is pointing to possible differentional computational stategies use differently by females and males when processing ethical information.
Using a “microcospe” to look at both the female´s brain and male´s brain we don´t see a different picture.
When a female sees red their light transducers work in the same manner as a male´s light trasnducers. Their respective photoreceptors apply the same laws of physics. Their respective retinal cells compute (at this level) with the same principles. But if we go depper, at the level of associative areas when things gone wild and complex with the intervention of past memories, emotive states…the computational outcome perhaps is really distinct indeed.
To be honest your question is a big issue because what is the level at which dimorphism is manifested in the “psychological” domain?. the molecular? the neural? the systemic? the computational? “the cognitive?”, the behavioural?
At the computational level is a big hurdle to give an straight answer. But if we take computations from the perspective of biophysics (Koch 1999 p. 1), it is possible that the biophysical variables that encode data attached to sensory signals embodied in a female body, could be different, not in the sense of using a totally different biochemistry or physics but in their time and intensity in which chemicals and laws are intermixed and used and ultimately in producing sexual differences
Returning to the complexity problem, I believe there are many places from wich we can start: paleoneurology (Harry Jerison or Ralph Holloway)studying evolution of brains in ancients animals; paleonthologists (J.L. Arsuaga)studiyng the lifestyle, physical biology and many other clues of past species; evolutionay anatomists (Pasko Rakic or Dean Falk)studying the mechanisms of cell differentiation and finally antrophologists (Steven Mithen) making sense of all
Hi Anibal,
I have to write briefly… but; let`s start with evolutionary psychology and the complexity- problem.
I have to admit that I am impressed: You seem to be very aware of paleoneurology and evolutionary approaches to brains. That`s brilliant, and yes – I am impressed.
However; as I wrote earlier the complexity challenge is a challenge mainly for evolutionary psychology, not neuropaleontology etc. The problem is this: Even if we had theories about evolution of ancient animal`s brains (and so on), we still do not have data or theory about their cognitive architecture and the selection pressures. Of course, an evolutionary psychologist could argue that “ok, we can simulate the behavior this and this kind of cognition game-theorically and see how the story would go”. But – if you are simulating the behavior, are you making a theory of cognition or cognitive abilities? I guess not… If you have no theory about the cognition of common ancestor, then you have no theory about the degree of cognitive complexity either. If you have only behavioral or neural data, it just does not do the job – what one needs is a neurocognitive data. Is there such data? If there is, then this argument may be wrong.
But of course; there will be other problems for evolutionary psychology…
I am sorry, I have to go now – but I´ll get back to the computational issues as soon as I can.
a
Anibal,
Part two. Since the space is limited, I cannot comment every part of your interesting reply. So, I have to “focus”, ok? But in general, I agree with you in many ways.
You wrote: “For example, C. Gilligan found empirical differences in the way females approach ethical thinking when confronted with ethical cases or scenarios in contrast to males (1982)
For her, females always solve ethical problems by consensus in a talkative spirit with main actors. On the other hand, males always solve ethical problems using rules and principles.”
This may be true, I have no problem with that. But the problem is that from the perspective of classical cognitive science these “rules”, “strategies” and “ethical thinking”s are central cognitive processes. And I guess that there may be somebody who whispers: “Children, children, try not to argue. I have written so many books about the central processes and the limits of computational approach.” I am not saying that this somebody would be necessary right, but… he is always worth to listen. So, it could be argued, that there are then problems with their computational status. This, of course, does not imply that they could not be – in principle – localizable into brains (if there is a reasonable way to do it).
However, there is another thing that should be mentioned. It is related to this: “But if we go depper, at the level of associative areas when things gone wild and complex with the intervention of past memories, emotive states…the computational outcome perhaps is really distinct indeed.”
Perhaps it is, yes – why not. But let`s take an example, a visual system. Baron-Cohen, for example, describes how males are better in visuo-spatial tasks. And let`s assume, just for the sake of the argument, that we can describe the computational mechanisms that are responsible for that particular cognitive ability.
Then the question is, how should we inteprete this result? Should we say that ok, there are just less “performance errors” in male brains in respect of those visuo spatial tasks? They just compute that kind of tasks better. And somehow there are more performance errors neurocomputational mechanisms in female brains? That they are “miscomputing” or “making computational errors” for many different reasons…
Or should we just simply say that the females and males are using completely different cognitive abilities? Are the tasks identical anymore…? What do you think?
From sunny Helsinki,
a
In relation to the lasts questions you have posed, wether there are distinct implementions of neurocomputational architectures leading to different cognitive abilities in males
or females, i think is not well understood nowadays.
But probably we are accumulating data to construct viable neurocomputational theories on sexual differences. Cognitive neuroscience, a discipline founded by M. Gazzaniga, perhaps is in the right track to arbiter pro or cons to sexual differences in cognition.
Correlating cognition with underlying attentional, linguistic, perceptual, decision-making, reasoning… procesess all of them with clear mapping onto brain areas, we can say men and women do not have different cognitive abilities.
Both have attentional, linguistic, perceptual, decision-making, reasoning… procesess.
I guess it is matter of indirect effects of chemicals and hormones, the distinct hormonal milieu within which males and females are and their lifespan effects and some genomic subtleties.
I wonder if artificial intelligence researchers adopting the roots of the computational theory of mind and firmly believing that every aspect of the mind is like a computer trying to implement their algorithms to create intelligent behaviour, if they are capable of say if their robots are “males” or “females”.
Maybe in information processing there is no sex.
But if we reject too much abstractionism and we consider that there´s something special in the “brain stuff” (organic tissue, neurotrasmitters, hormones…)then differences emerge.
It is a worth line of investigation to pursue and explore,say, the computational sexual diffrences in cognition. An because you are a keen expert in computational matters it´s something that belongs to your expertise.